Answer:
10 seconds.
Explanation:
We can use a kinematic equation where we know the final velocity, initial velocity, acceleration, and need to determine the time <em>t: </em>
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The initial velocit is 30 m/s, the final velocity is 0 m/s (as we stopped), and the acceleration is -3 m/s².
Substitute and solve for <em>t: </em>
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Hence, it will take the car 10 seconds to come to a stop.
<span>If there isn't any force then the normal contact force will be
N=m*g=7.5*9.81=73.58N
which is 73.58-23=50.58N less
so, there the person must pull at 23 degree upward
break down the tension in two components, vertical and horizontal.
vertical tension= 50.58=T*sin23
T=50.58/sin23=129.45N</span>
Answer:

Explanation:
When we push the box from the bottom of the incline towards the top then by work energy theorem we can say that
Work done by all the forces = change in kinetic energy of the system

here we know that

also we know that the length of the incline is given as

now we have

so we have
